The remarks were made following the latest attack in which a Syrian refugee set off a bomb near a music festival in the southern town of Ansbach late Sunday, killing himself and injuring a dozen others, PressTV reported.
Earlier on Sunday, a machete-wielding Syrian refugee attacked several people in southwestern Germany, killing one person and injuring two others.
On Friday, nice people were killed during a mass shooting by a teenager in a shopping mall in the city of Munich and on July 18, an ax attack injured several on a train on Wurzburg.
“Each of these cases is one too many,” said de Maiziere, adding, “I understand, that many people are unsettled and worried. I can assure you: our state is strong and will remain strong, on a federal level as well as on a regional level. Our security agencies are well prepared. They will continue to do whatever is necessary to ensure, that this kind of act will not happen again.”
Earlier in the day, he warned that his nation should not alter their behavior towards refugees, but should still remain cautious.
“We must not place refugees under general suspicion despite individual cases that are under investigation,” he said.